(Upper left) Chemical bonding and physical structure of red-light absorbing carbon nitride sheets. (Lower left) In a liquid state, red light is transmitted at a maximum of 450nm and emitted at a wavelength of 635 nm. (Right) After 4 weeks of loading the sheets into the skull-damaged mice, the skull was regenerated by more than 90 percent. Photo courtesy of UNIST
Feb. 8 (UPI) -- Researchers from Ulsan National Institute of Science and Technology in South Korea, or UNIST, have developed a method of repairing bone using a mix of stem cells and a carbon material with photocatalytic properties.
Prior studies have used human bone marrow-derived mesenchymal stem cells, or hBMSCs, to treat fractures because of their potential to regenerate bone in patients who have lost large areas of bone from disease or trauma.
To enhance the function of stem cells, researchers have used carbon nanotubes, graphene and nano-oxides.
In this study, researchers used red-light absorbing carbon nitride sheets that showed proliferation and osteogenic differentiation by runt-related transcription factor 2, or Runx2, activation.
Researchers found that this material absorbs red light and then emits fluorescence that can be used to hasten bone regeneration. Stem cells and cancer cells were cultured in a mix containing red-light absorbing carbon nitride sheets, and after two days the material showed no cytotoxicity, making it suitable as a biomaterial.
The study also showed that red-light absorbing carbon nitride sheets act on stem cells to differentiate into osteoblasts to promote mineral formation, which resulted in accelerated bone formation.
"This research has opened up the possibility of developing a new medicine that effectively treats skeletal injuries, such as fractures and osteoporosis," Professor Young-Kyo Seo of the Life Sciences Department at UNIST and co-author of the study, said in a press release. "It will be a very useful tool for making artificial joints and teeth with the use of 3D printing."
Seo collaborated on the study with Dr. Jitendra N. Tiwari, Professor Kwang S. Kim and Professor Pann-Ghill Suh along with other researchers at UNIST.
"This is an important milestone in the analysis of biochemical functions needed for the development of biomaterials, including adjuvants for hard tissues such as damaged bones and teeth," Seo said.
The study was published in ACS Nano.